Induction Chemotherapy Response-Guided Reduced-Dose Radiotherapy for Nasopharyngeal Carcinoma

This study focused on patients with AJCC/UICC 9th edition stage IB‐II（The participantswere required to have no extensive skull base invasion and lymph nodes < 4 cm beforetreatment）. It aimed to adaptively guide the reduction of radiation dose fornasopharyngeal carcinoma based on the response to induction chemotherapy, therebyminimizing radiation‐related toxicity while ensuring local control. Cohort 1 was randomlyassigned 1:1 to the 59.4 Gy/27 fractions group and the 66.0 Gy/30 fractions group andcompared their LRFFS. The participants were required to have EBV‐DNA = 0 and CR or PR >50% after 2 courses of induction therapy. Those who did not meet the criteria wereassigned to Cohort 2 to receive standard‐dose radiotherapy combined with concurrentcisplatin to avoid excessive reduction of intensity for potentially high‐risk patients.